1. Field of the Invention
The invention relates in general to a wide-angle lens and a projection device using the same, and more particularly to a wide-angle lens having three lens groups and a projection device using the same.
2. Description of the Related Art
The projection distance of a projection device is related to the size of the to-be-displayed image. The farther away from the screen the projection device is, the larger the projected image will be. However, the projection distance is often restricted by the hardware and the space. Thus, how to project a large image with a limited projection distance has become a focus in the industry of projection device.